An efficient organocatalytic Michael-aldol cascade reaction for the asymmetric synthesis of spirocyclic oxindole derivatives fused with tetrahydrothiophenes has been developed through a formal [3+2] annulation strategy.
Exploration of A New Zwitterion: Phosphine-Catalyzed [2+1+2] Cycloaddition Reaction
作者:Yu-Ning Gao、Qin Xu、Yin Wei、Min Shi
DOI:10.1002/adsc.201700242
日期:2017.5.17
A new zwitterion generated from different electron‐deficient alkenes and phosphines has been designed and its reactivity was explored. We demonstrated that this new zwitterion directed a novel [2+1+2] cycloaddition reaction between vinylpyridines and isatin‐derived electron‐deficient alkenes, affording spirocyclopenteneoxindole derivatives containing three stereocenters in moderate to good yields with